iwlwifi: disable the buggy chain extension feature in HW
commit d012d04e4d6312ea157b6cf19e9689af934f5aa7 upstream.
This feature has been reported to be buggy and enabled by
default. We therefore need to disable it manually.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index 4d7b30d..66df016 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -1128,6 +1128,11 @@
iwl_write_prph(trans, SCD_DRAM_BASE_ADDR,
trans_pcie->scd_bc_tbls.dma >> 10);
+ /* The chain extension of the SCD doesn't work well. This feature is
+ * enabled by default by the HW, so we need to disable it manually.
+ */
+ iwl_write_prph(trans, SCD_CHAINEXT_EN, 0);
+
/* Enable DMA channel */
for (chan = 0; chan < FH_TCSR_CHNL_NUM ; chan++)
iwl_write_direct32(trans, FH_TCSR_CHNL_TX_CONFIG_REG(chan),